A selective increase in COX-1 mRNA expression in the hippocampus of aged rats was shown which was possibly causing an increased susceptibility to neuroinflammation (22) and also COX-1-expressing microglia are found surrounding the amyloid plaques in the AD brain indicating a role of this isoform in the pathophysiology of the disease (21, 23). This evidence concerns the gene PTGS1 and Alzheimer disease.